(function () {
    var a = ['155', '65'];
    var b = ['123456789', '123456789'];
    var c = ['887987345974539','4582796427862587'];
    var d = ['347135713985789531798031509832579382573195807',
        '817651358763158761358796358971685973163314321'];

    var resultA = '220';
    var resultB = '246913578';
    var resultC = '5470783773837126';
    var resultD = '1164787072748948293156827868804265355736510128';

    var a0 = new BigInteger(a[0]);
    var a1 = new BigInteger(a[1]);
    var b0 = new BigInteger(b[0]);
    var b1 = new BigInteger(b[1]);
    var c0 = new BigInteger(c[0]);
    var c1 = new BigInteger(c[1]);
    var d0 = new BigInteger(d[0]);
    var d1 = new BigInteger(d[1]);

    
    console.log(a0.add(a1).toString() === resultA);
    console.log(b0.add(b1).toString() === resultB);
    console.log(c0.add(c1).toString() === resultC);
    console.log(d0.add(d1).toString() === resultD);
}());